Ubuntu Boot Error --- Missing modules (cat /proc/modules; ls /dev)

Boot from (hd0,0) ext3 5108701a-641d-43b182eb-aeb6da348d62Starting up ...Loading, please wait...Gave up waiting for root device. Common problems:- Boot args (cat /proc/cmdline)- Check rootdelay= (did the system wait long enough ?)- Check root = (did the system wait for the right device ?)- Missing modules (cat /proc/modules; ls /dev)ALERT! /dev/disk/by-uuid/5108701a-641d-43b182eb-aeb6da348d62 does notexist . Dropping to a shell!Busybox v1.10.2 (Ubuntu 1:1.10.2-2ubuntu7) built-in shell (ash)Enter 'help' for a list of built-in commands.(initramfs)Just boot ubuntu by selecting another option of booting ubuntu from grub menu at startup, and upgrade ubuntu as per the steps given below

Network Upgrade for Ubuntu Desktop

You can easily upgrade over the network with the following procedure.

Start System/Administration/Update Manager

Click the Check button to check for new updates.

If there are any updates to install, use the Install Updates button to install them, and press Check again after that is complete.

A message will appear informing you of the availability of the new release.

Click Upgrade.

Follow the on-screen instructions.

If during upgrade an error is generated, then you will be given a command to enter into the terminal mode.Enter that command in terminal mode, you will be asked to modify grub menu, select first option to modify grub menu (do not select keep exisiting menu).Then go to updater and update it.You are doneRestart the pc and boot by selecting the normal mode of ubuntu from grub menu...